In a display device that may be used under circumstances where the device is forced to be driven at a low temperature in an airplane, automobile and the like, a panel heater has conventionally been used to heat the used display panel for a while after power-on of the device or if required, to get the operational temperature to an appropriate temperature. Particularly, in the liquid crystal material used as a display medium in a liquid crystal display panel, response characteristics and other display operational characteristics deteriorate under low-temperature circumstances, and so the material requires to maintain the operational temperature at an appropriate temperature by the panel heater.
Conventional techniques for such a panel heater include one described in Patent Document 1. In the panel heater described in the Document, a transparent conductive film is formed on a substrate, an electrode terminal to apply a voltage to the transparent conductive film is provided on a flexible wiring substrate, the electrode terminal and the transparent conductive film are pressure-bonded to be conductive via an anisotropic conductive material wherein conductive particles are mixed into an adhesive with the anisotropic conductive material sandwiched between the transparent conductive film and the electrode terminal, and the transparent conductive film is heated by applying a voltage to the transparent conductive film through the electrode terminal to warm liquid crystal display elements. Instead of forming the electrode terminal merely in the shape of a band with a constant width, the electrode terminal is provided on its edge portion with a plurality of inflow openings such that the anisotropic conductive material flows thereinto when the electrode terminal is pressure-bonded onto the transparent conductive film. By this means, the anisotropic conductive material is prevented from remaining at the edge portion of the electrode terminal, and the surface area of an end face on the edge-portion side of the electrode terminal, thereby improving the adhesion to the transparent conductive film.
[Patent Document 1] JP2002-23186 (see particularly, FIGS. 1, 2 and 6, Claims, and paragraph numbers [0015] to [0020], [0029], [0030], [0034] and [0035])